Hispanic Americans are one of the fastest growing ethnic groups in the US and the group with the highest prevalence of obesity across all ages. Obesity prevention needs to start from early childhood through the promotion of an active lifestyle. Although there is growing empirical support for associations between aspects of the physical and social environments and physical activity (PA) behavior, these issues, as they pertain to Hispanic-American (HA) children, remain understudied. Many HA children live in unsafe and under-resourced communities and have no health insurance coverage. Hence, it is particularly urgent to conduct a systematic evaluation of modifiable environmental facilitators and deterrents of PA relevant to this segment of the population. Such evaluation needs to start with the development of a culturally-sensitive model of environment- PA relationships and relevant measures. The present study aims to 1) identify primary caregivers'practices and aspects of the neighborhood environment that potentially influence the PA behavior of HA preschool children, and 2) develop measures of the social and physical environments, and locations where PA occurs, that will permit a rigorous study of environmental influences on PA in this population segment. Sixty-four HA primary caregivers of 3-to-5 year old children will participate in structured focus groups aimed at identifying key aspects of 1) caregivers'practices related to preschoolers'PA, 2) the neighborhood social environment, 3) perceived neighborhood safety, 4) places for PA, 5) and active-play equipment. This information will be used to develop questionnaires of these five concepts. Qualitative cognitive interviews will be conducted on another sample of 20 HA primary caregivers in order to refine the newly-developed questionnaires. Census block groups in urban Houston (Texas) will be screened and selected for study based on percentage of HA residents, availability of recreation space, and neighborhood safety (risk of crime and traffic safety). A sample of 240 HA primary caregivers of preschool children will be recruited from the selected areas. They will complete the newly-developed questionnaires. Half of these primary caregivers (n=120) will be asked for consent to their child's participation in the study. Children's PA will be measured for four days using small activity monitors. Locations of PA will be recorded using compact Global Positioning System monitors and caregivers'diaries. Data on family socio-demographics, acculturation, familism, and ethno-cultural identity will also be collected. The proposed trans-disciplinary project team combines expertise in measurement development and study of obesity, physical activity, parental practices, and built environment factors proposed to be related to PA in HA preschoolers. This project will identify family and neighborhood characteristics contributing to PA in HA preschoolers to guide future environmental and educational interventions aimed at combating the obesity plague in the HA ethnic group from early life. PUBLIC HEALTH RELEVANCE: Childhood obesity has reached epidemic proportions in this country, especially among Hispanic American children. This project will identify primary caregivers'and neighborhood characteristics contributing to obesity in Hispanic-American preschoolers. This knowledge will guide future environmental and educational interventions aimed at combating the obesity plague in the Hispanic-American ethnic group from early life.